There are presently many different types of bone plate systems for securing bones so that the secured bones may fuse or heal. As used herein, the term bone may refer to a bone, a bone fragment, or a portion of a bone. One application for bone plate systems is repairing one or more ribs after a thoracotomy. A thoracotomy may involve cutting a rib or, in some instances, removing a section of a rib in order to provide access to tissues and organs within the chest cavity of a patient.
After the tissues or organs within the chest cavity have been operated upon, the ribs of the patient may need to be repaired. For example, if one of the ribs has been cut, a bone plate and screws may be used to secure the portions of the cut rib together. However, rib bones are relatively thin such that driving the screws into the portions of the cut rib exerts an outward pressure upon the bone which may splinter the bone. Further, rib bones consist of soft cancellous bone enclosed in a thin, compact layer of hard cortical bone. In order to achieve sufficient purchase in the bone, the screws may need to be driven completely through both layers of cortical bone and the cancellous bone therebetween. This may cause a portion of a screw shank to extend beyond the rib and irritate tissues within the chest cavity of the patient.
A thoracotomy may also involve using a retraction device to retract a pair of ribs of a patient apart in order to provide access to the tissues or organs within a patient's chest cavity. The retracted ribs may not return to their original position after the retraction device has been removed, which may be due to breaking of the surrounding bones and/or cartilage. In one approach, suture wire is looped around the pair of ribs and tightened to approximate the pair of ribs back together. However, each rib has a delicate neurovascular bundle of a vein, an aertery, and a nerve extending along the underside of the rib such that tightening the looped suture wire around the ribs may undesirably pinch the neurovascular bundle of one or more of the ribs.
In some thoracotomy procedures, a rib is cut and the portions of the cut rib are manipulated in order to gain access to a patient's chest cavity and, after the chest cavity has been accessed, a bone plate is used to promote post-operative fusion of the rib portions. More specifically, once the tissues or organs within the chest cavity have been accessed, the rib portions are approximated to return the rib portions to their initial positions. Pilot holes are drilled in the rib portions near the cut ends of the rib portions. Next, a bone plate is positioned on the rib portions so that throughbores of the bone plate are aligned with the pilot holes and the bone plate extends across the cut in the rib. Bone screws are driven through the bone plate throughbores to secure the bone plate to the rib portions and stabilize the rib and bone plate construct. One problem with this approach is that drilling the pilot holes in the rib portions may be difficult because the rib portions are hard to manipulate after being cut. Another problem is that obtaining a precise alignment of the pilot holes in the rib portions and the throughbores of the bone plate is challenging due to the difficulty in drilling properly spaced and oriented pilot holes in the cut rib portions.